From: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Adding packet and byte quota support. Once a quota has been
reached a noticifaction is sent to user space that includes
the name of the accounting object along with the current byte
and packet count.
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
include/linux/netfilter/nfnetlink_acct.h | 15 ++-
include/uapi/linux/netfilter/nfnetlink.h | 2 +
include/uapi/linux/netfilter/nfnetlink_acct.h | 1 +
include/uapi/linux/netfilter/xt_nfacct.h | 14 ++-
net/netfilter/Kconfig | 3 +-
net/netfilter/nfnetlink_acct.c | 50 ++++++---
net/netfilter/xt_nfacct.c | 139 ++++++++++++++++++++++++--
7 files changed, 194 insertions(+), 30 deletions(-)
diff --git a/include/linux/netfilter/nfnetlink_acct.h b/include/linux/netfilter/nfnetlink_acct.h
index b2e85e5..3353390 100644
--- a/include/linux/netfilter/nfnetlink_acct.h
+++ b/include/linux/netfilter/nfnetlink_acct.h
@@ -3,11 +3,20 @@
#include <uapi/linux/netfilter/nfnetlink_acct.h>
-
-struct nf_acct;
+struct nf_acct {
+ atomic64_t pkts;
+ atomic64_t bytes;
+ struct list_head head;
+ atomic_t refcnt;
+ char name[NFACCT_NAME_MAX];
+ struct rcu_head rcu_head;
+ spinlock_t lock;
+};
struct nf_acct *nfnl_acct_find_get(const char *filter_name);
void nfnl_acct_put(struct nf_acct *acct);
-void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct);
+extern void nfnl_acct_update(const struct sk_buff *skb,
+ struct nf_acct *nfacct, u64 *pkts, u64 *bytes);
+void nfnl_quota_event(struct nf_acct *cur);
#endif /* _NFNL_ACCT_H */
diff --git a/include/uapi/linux/netfilter/nfnetlink.h b/include/uapi/linux/netfilter/nfnetlink.h
index 596ddd4..354a7e5 100644
--- a/include/uapi/linux/netfilter/nfnetlink.h
+++ b/include/uapi/linux/netfilter/nfnetlink.h
@@ -20,6 +20,8 @@ enum nfnetlink_groups {
#define NFNLGRP_CONNTRACK_EXP_DESTROY NFNLGRP_CONNTRACK_EXP_DESTROY
NFNLGRP_NFTABLES,
#define NFNLGRP_NFTABLES NFNLGRP_NFTABLES
+ NFNLGRP_ACCT_QUOTA,
+#define NFNLGRP_ACCT_QUOTA NFNLGRP_ACCT_QUOTA
__NFNLGRP_MAX,
};
#define NFNLGRP_MAX (__NFNLGRP_MAX - 1)
diff --git a/include/uapi/linux/netfilter/nfnetlink_acct.h b/include/uapi/linux/netfilter/nfnetlink_acct.h
index c7b6269..ae8ea0a 100644
--- a/include/uapi/linux/netfilter/nfnetlink_acct.h
+++ b/include/uapi/linux/netfilter/nfnetlink_acct.h
@@ -19,6 +19,7 @@ enum nfnl_acct_type {
NFACCT_PKTS,
NFACCT_BYTES,
NFACCT_USE,
+ NFACCT_QUOTA,
__NFACCT_MAX
};
#define NFACCT_MAX (__NFACCT_MAX - 1)
diff --git a/include/uapi/linux/netfilter/xt_nfacct.h b/include/uapi/linux/netfilter/xt_nfacct.h
index 3e19c8a..c4d7674 100644
--- a/include/uapi/linux/netfilter/xt_nfacct.h
+++ b/include/uapi/linux/netfilter/xt_nfacct.h
@@ -3,11 +3,23 @@
#include <linux/netfilter/nfnetlink_acct.h>
+enum xt_quota_flags {
+ XT_NFACCT_QUOTA_PKTS = 1 << 0,
+ XT_NFACCT_QUOTA = 1 << 1,
+};
+
struct nf_acct;
struct xt_nfacct_match_info {
char name[NFACCT_NAME_MAX];
- struct nf_acct *nfacct;
+ struct nf_acct *nfacct __aligned(8);
};
+struct xt_nfacct_match_info_v1 {
+ char name[NFACCT_NAME_MAX];
+ struct nf_acct *nfacct __aligned(8);
+
+ __u32 flags;
+ __aligned_u64 quota;
+};
#endif /* _XT_NFACCT_MATCH_H */
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index 748f304..ce184951 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -1108,7 +1108,8 @@ config NETFILTER_XT_MATCH_NFACCT
select NETFILTER_NETLINK_ACCT
help
This option allows you to use the extended accounting through
- nfnetlink_acct.
+ nfnetlink_acct. It is also possible to add quotas at the
+ packet and byte level.
To compile it as a module, choose M here. If unsure, say N.
diff --git a/net/netfilter/nfnetlink_acct.c b/net/netfilter/nfnetlink_acct.c
index 225a886..8d23a15 100644
--- a/net/netfilter/nfnetlink_acct.c
+++ b/net/netfilter/nfnetlink_acct.c
@@ -29,16 +29,6 @@ MODULE_DESCRIPTION("nfacct: Extended Netfilter accounting infrastructure");
static LIST_HEAD(nfnl_acct_list);
-struct nf_acct {
- atomic64_t pkts;
- atomic64_t bytes;
- struct list_head head;
- atomic_t refcnt;
- char name[NFACCT_NAME_MAX];
- struct rcu_head rcu_head;
- spinlock_t lock;
-};
-
static int
nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
const struct nlmsghdr *nlh, const struct nlattr * const tb[])
@@ -96,7 +86,7 @@ nfnl_acct_new(struct sock *nfnl, struct sk_buff *skb,
return 0;
}
-static int
+int
nfnl_acct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
int event, struct nf_acct *acct)
{
@@ -141,6 +131,7 @@ nla_put_failure:
nlmsg_cancel(skb, nlh);
return -1;
}
+EXPORT_SYMBOL_GPL(nfnl_acct_fill_info);
static int
nfnl_acct_dump(struct sk_buff *skb, struct netlink_callback *cb)
@@ -336,15 +327,46 @@ void nfnl_acct_put(struct nf_acct *acct)
}
EXPORT_SYMBOL_GPL(nfnl_acct_put);
-void nfnl_acct_update(const struct sk_buff *skb, struct nf_acct *nfacct)
+void nfnl_acct_update(const struct sk_buff *skb,
+ struct nf_acct *nfacct, u64 *pkts, u64 *bytes)
{
+ u64 lpkts, lbytes;
+
spin_lock_bh(&nfacct->lock);
- atomic64_inc(&nfacct->pkts);
- atomic64_add(skb->len, &nfacct->bytes);
+ lpkts = atomic64_inc_return(&nfacct->pkts);
+ lbytes = atomic64_add_return(skb->len, &nfacct->bytes);
spin_unlock_bh(&nfacct->lock);
+
+ if (pkts)
+ *pkts = lpkts;
+ if (bytes)
+ *bytes = lbytes;
}
EXPORT_SYMBOL_GPL(nfnl_acct_update);
+void
+nfnl_quota_event(struct nf_acct *cur)
+{
+ int ret;
+ struct sk_buff *skb;
+
+ skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+ if (skb == NULL)
+ return;
+
+ ret = nfnl_acct_fill_info(skb, 0, 0, NFACCT_QUOTA,
+ NFNL_MSG_ACCT_NEW, cur);
+
+ if (ret <= 0) {
+ kfree_skb(skb);
+ return;
+ }
+
+ netlink_broadcast(init_net.nfnl, skb, 0,
+ NFNLGRP_ACCT_QUOTA, GFP_ATOMIC);
+}
+EXPORT_SYMBOL_GPL(nfnl_quota_event);
+
static int __init nfnl_acct_init(void)
{
int ret;
diff --git a/net/netfilter/xt_nfacct.c b/net/netfilter/xt_nfacct.c
index b3be0ef..63ca22f 100644
--- a/net/netfilter/xt_nfacct.c
+++ b/net/netfilter/xt_nfacct.c
@@ -8,9 +8,12 @@
*/
#include <linux/module.h>
#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <net/netlink.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/nfnetlink_acct.h>
+#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/xt_nfacct.h>
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>");
@@ -23,11 +26,86 @@ static bool nfacct_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_nfacct_match_info *info = par->targinfo;
- nfnl_acct_update(skb, info->nfacct);
+ nfnl_acct_update(skb, info->nfacct, NULL, NULL);
return true;
}
+/* Someone in the system may be upgrading 'info' at any moment.
+ * To avoid using a lock we simply make sure the packet count
+ * hasn't increased while we were updating the byte count.
+ */
+static void
+nfacct_get_values(const struct xt_nfacct_match_info_v1 *info,
+ u64 *pkts, u64 *bytes) {
+ u64 old_pkts, new_pkts, lbytes;
+
+repeat:
+ old_pkts = atomic64_read(&info->nfacct->pkts);
+ lbytes = atomic64_read(&info->nfacct->bytes);
+ new_pkts = atomic64_read(&info->nfacct->pkts);
+
+ if (old_pkts != new_pkts)
+ goto repeat;
+
+ *pkts = new_pkts;
+ *bytes = lbytes;
+}
+
+static bool
+nfacct_mt_v1(const struct sk_buff *skb, struct xt_action_param *par)
+{
+ int packet_mode;
+ u64 val;
+ u64 old_pkts, new_pkts, old_bytes, new_bytes;
+ const struct xt_nfacct_match_info_v1 *info = par->matchinfo;
+ bool ret = true;
+
+ /* get a reference count */
+ nfacct_get_values(info, &old_pkts, &old_bytes);
+ /* upgrade accounting stats */
+ nfnl_acct_update(skb, info->nfacct, &new_pkts, &new_bytes);
+
+ /* no need to go further if we don't have a quota */
+ if (!(info->flags & XT_NFACCT_QUOTA))
+ return ret;
+
+ packet_mode = info->flags & XT_NFACCT_QUOTA_PKTS;
+
+ val = (packet_mode) ? new_pkts : new_bytes;
+
+ /* are we over the limit ? */
+ if (val <= info->quota)
+ ret = !ret;
+
+ /* see if we need to tell userspace */
+ if (packet_mode) {
+ /* Easy case - send notification if we are handling the
+ * packet that got us over quota.
+ */
+ if (old_pkts < info->quota &&
+ new_pkts >= info->quota &&
+ old_pkts + 1 == new_pkts)
+ nfnl_quota_event(info->nfacct);
+ } else {
+ /* Need to be careful in byte mode - if nobody got in front
+ * of us simply check if we are over quota. If someone got
+ * faster we need to see if they sent a notification by
+ * checking how many bytes they contributed.
+ *
+ * If what they contributed went over quota they sent the
+ * notification, otherwise we need to do so.
+ */
+ if (old_pkts + 1 != new_pkts)
+ old_bytes = new_bytes - skb->len;
+
+ if (old_bytes < info->quota && val >= info->quota)
+ nfnl_quota_event(info->nfacct);
+ }
+
+ return ret;
+}
+
static int
nfacct_mt_checkentry(const struct xt_mtchk_param *par)
{
@@ -44,6 +122,24 @@ nfacct_mt_checkentry(const struct xt_mtchk_param *par)
return 0;
}
+static int
+nfacct_mt_checkentry_v1(const struct xt_mtchk_param *par)
+{
+ struct xt_nfacct_match_info_v1 *info = par->matchinfo;
+ struct nf_acct *nfacct;
+
+ nfacct = nfnl_acct_find_get(info->name);
+ if (nfacct == NULL) {
+ pr_info("xt_nfacct: invalid accounting object `%s'\n",
+ info->name);
+ return -ENOENT;
+ }
+
+ info->nfacct = nfacct;
+
+ return 0;
+}
+
static void
nfacct_mt_destroy(const struct xt_mtdtor_param *par)
{
@@ -52,24 +148,45 @@ nfacct_mt_destroy(const struct xt_mtdtor_param *par)
nfnl_acct_put(info->nfacct);
}
-static struct xt_match nfacct_mt_reg __read_mostly = {
- .name = "nfacct",
- .family = NFPROTO_UNSPEC,
- .checkentry = nfacct_mt_checkentry,
- .match = nfacct_mt,
- .destroy = nfacct_mt_destroy,
- .matchsize = sizeof(struct xt_nfacct_match_info),
- .me = THIS_MODULE,
+static void
+nfacct_mt_destroy_v1(const struct xt_mtdtor_param *par)
+{
+ const struct xt_nfacct_match_info_v1 *info = par->matchinfo;
+
+ nfnl_acct_put(info->nfacct);
+}
+
+static struct xt_match nfacct_mt_reg[] __read_mostly = {
+ {
+ .name = "nfacct",
+ .family = NFPROTO_UNSPEC,
+ .checkentry = nfacct_mt_checkentry,
+ .match = nfacct_mt,
+ .destroy = nfacct_mt_destroy,
+ .matchsize = sizeof(struct xt_nfacct_match_info),
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "nfacct",
+ .revision = 1,
+ .family = NFPROTO_UNSPEC,
+ .checkentry = nfacct_mt_checkentry_v1,
+ .match = nfacct_mt_v1,
+ .destroy = nfacct_mt_destroy_v1,
+ .matchsize = sizeof(struct xt_nfacct_match_info_v1),
+ .me = THIS_MODULE,
+ },
+
};
static int __init nfacct_mt_init(void)
{
- return xt_register_match(&nfacct_mt_reg);
+ return xt_register_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
}
static void __exit nfacct_mt_exit(void)
{
- xt_unregister_match(&nfacct_mt_reg);
+ xt_unregister_matches(nfacct_mt_reg, ARRAY_SIZE(nfacct_mt_reg));
}
module_init(nfacct_mt_init);
--
1.8.3.2
--
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